1. Field of the Invention
The present invention relates to a power driven surgical saw blade and more particularly relates to a surgical saw blade having a prearranged hub section which is configured to be driven in an oscillating manner by a pneumatic or electrically powered actuator having a clamp for removeably mounting the blade. The prearranged hub section includes slots having generally rectangular elongated blade driving enabling sections each of which terminate in unexpanded bulbous blade driving disabling section which is configured for disengaging from a plurality of driving circular pins arranged in a pattern by deflecting a driving force therefrom along a locus of points which avoids driving the surgical saw blade in response to a driving force therefrom.
2. Description of the Prior Art
Powered saws are frequently used for surgical procedures including orthopedic surgery, and other operations requiring removal of bone material. A surgical saw blade, the blade clamp, and blade drive must be compatible to effective use the same. Typically, the saw blade has a low blade weight to minimize oscillating mass and the hub section is configured to enable a secure mounting or clamping of the surgical saw blade to a selected saw blade driver. The hub section is configured to enable a saw blade to be used with a designated number of saw blade drivers. It is known in the art to refer to such saw blades as universal saw blades.
The prior art includes a variety of cooperating blades, clamps and oscillating drive mechanisms which are configured to be used with a surgical saw blade having a specially configured hub section.
U.S. Pat. No. 5,265,343 discloses a blade and a corresponding clamp mechanism which provides, by the circular arrangement of round driving pins and clamping faces, a secure mount for the blade by way of the cooperating holes in the hub section of the surgical saw blade. One set of blades for use in a clamp such as described in U.S. Pat. No. 5,265,343 is shown as FIGS. 5A through 5C in U.S. Pat. No. 5,306,285. Another blade, for use in a clamp similar to the clamp described in U.S. Pat. No. 5,265,343 is shown in FIG. 6A of U.S. Pat. No. 5,306,285.
Another clamp mechanism and associated blade hub is shown in U.S. Pat. Nos. 5,496,316 and 5,489,285. The clamp described in the in U.S. Pat. Nos. 5,496,316 and 5,489,285 is similar in function to the clamp described in U.S. Pat. No. 5,265,343 except that the clamp described in the in U.S. Pat. Nos. 5,496,316 and 5,489,285 use rectangular driving lugs instead of round driving pins.
The rectangular driving lugs shown in U.S. Pat. Nos. 5,496,316 and 5,489,285 and the round driving pins shown in U.S. Pat. No. 5,265,343 are both arranged in a circular pattern and both have clamping faces. The clamps described in U.S. Pat. No. 5,265,343 and U.S. Pat. No. 5,496,316 both have means for biasing the blade against one clamping face.
Another related prior art saw blade configured for use with a rectangular lug clamp, such as that shown in the U.S. Pat. No. 5,496,316 is shown in U.S. Design Pat. DES 343,247. The blade hub shown in the U.S. Design Pat. DES 343,247 has radial slots formed to fit lugs, such as the lugs shown in U.S. Pat. No. 5,496,316. The radial slots shown in U.S. Design Pat. DES 343,247 are closed at both ends. This is different in form than the slot shown in U.S. Pat. No. 5,496,316 that are open to and communicate with the primary U-shaped slot.
It is known in the art that the LINVATEC-HALL VERSIPOWER.RTM.PLUS OSCILLATOR has a clamp substantially identical in structure, function, and operation as the clamp shown in U.S. Pat. No. 5,496,316.
It is also known in the art that the LINVATEC-HALL SERIES 3.™. and LINVATEC-HALL SERIES 4.™. device contain a clamp substantially identical in structure and function to clamp described in U.S. Pat. No. 5,265,343.
The MicroAire.RTM. Powermaster.™. 7200 Oscillating Saw contains a clamp which mounts blades interchangeably with saw blades shown in clamps described in U.S. Pat. No. 5,694,693.
For proper operation using clamps of the form shown in U.S. Pat. No. 5,265,343, the round holes formed in the blade hub must precisely fit and cooperate with the round locking driving pins of the saw blade driver. The reason is that radial motion to the saw blade is imparted through the driving pins and any clearance between the blade holes and the round pins will allow motion or relative movement of the pins within the hub holes. As mismatch may result in erratic blade motion, accelerated wear on the round driving pins and possible fatigue-related failure in the blade hub.
Likewise, the lugs of the clamp shown in U.S. Pat. No. 5,496,316 must fit snug against the radial slots of the blade. Accordingly, a saw blade hub formed to fit the round driving pins of the clamp shown in U.S. Pat. No. 5,265,343 will not have the elongated slots required for the rectangular lugs of the clamp shown in U.S. Pat. No. 5,496,316. Further, a saw blade having slots formed and dimensioned such for use in the clamp shown in U.S. Pat. No. 5,496,316 will not fit properly with the round driving pins shown in the clamp shown in U.S. Pat. No. 5,265,343 unless the rectangular lugs have the same width as the diameter of the round pins.
U.S. Pat. No. 5,694,693 discloses a universal saw blade hub that is configured to be operative with the clamps shown in U.S. Pat. Nos. 5,496,316 and 5,265,343.
Further the saw blade shown in FIG. 5 of U.S. Pat. No. 5,496,316 appears to be able to fit either a round driving pin clamp shown in U.S. Pat. No. 5,265,343 or rectangular lug clamp shown in U.S. Pat. No. 5,496,316. The saw blade shown in FIG. 5 of U.S. Pat. No. 5,496,316 appears to achieve this objective by having enlarged circular openings at the outer end of each of the slots wherein the holes having a wider diameter than the width of the slot.
It is also known in the art that a saw blade driving clamp may have rectangular driving lugs which terminate in a substantially circular outer ends. One example of such a blade is shown in U.S. Pat. No. 5,496,316.
Under certain circumstances, it may be desirable design and fabricate a saw blade which is configured to be driven only by certain selected saw blade drivers and to not be driveable by another saw blade driver. None of the saw blades drivers or saw blades known in the art anticipate, disclose, suggest or teach a prearranged hub section which is configured to have slots which can be engaged and driven by a rectangular lugs terminating in a substantially rectangular outer end arranged in a pattern or a plurality of driving rectangular lugs terminating in a substantially circular outer end arranged in a pattern to drive the saw blade and wherein each slot has an expanded bulbous blade driving disabling section configured to prevent being driven by a plurality of driving circular pins arranged in a pattern.